A ring wire through your lamp (you say it's a circular one) may work really well for capacitive sensor. They can be made really sensitive (look at how a theremin works). Least bulky for sure, but stands and falls with proper grounding.
A ring wire through your lamp (you say it's a circular one) may work really well for capacitive sensor. They can be made really sensitive (look at how a theremin works). Least bulky for sure, but stands and falls with proper grounding.